There is a parametric speaker as one of speakers. For example, as disclosed in Patent Document 1, the parametric speaker modulates an audio signal into a modulation signal of an ultrasonic wave band, and demodulates the modulation signal into an audible sound in the atmosphere.
As an oscillation device that oscillates a sonic wave of an ultrasonic wave band, there is a device in which a piezoelectric element is used as a vibrator (for example, Patent Documents 1 to 4). When a piezoelectric element is used as a vibrator, it is necessary to form electrodes on both sides of the piezoelectric element, and to input a signal between the two electrodes. Patent Documents 1 and 2 of these Patent Documents disclose that a terminal for inputting a signal to the electrode located on the upper surface side of the piezoelectric element utilizes a spring.
Meanwhile, Patent Document 5 discloses that in a piezoelectric actuator, a piezoelectric element is supported by a power feeding support portion through an elastic body.